The benefit of the magnetic breakaway is that it works at any angle, which is a reduced risk in certain theft scenarios. In any case, we have a guide on how you can build one yourself here:
I doubt frying the motherboard would have any impact on the irrecoverability of the data on the disk. If you want to do this properly, we have an anti-forensics “self-destruct” trigger that wipes the FDE (encryption keys from the) LUKS header:
The benefit of the magnetic breakaway is that it works at any angle, which is a reduced risk in certain theft scenarios. In any case, we have a guide on how you can build one yourself here: